This invention relates generally to photography and more particularly to a disposable or single use assembly for developing exposed radiation sensitive-film.
Disposable or single use film developers such as described in U.S. Pat. Nos. 3,680,464, 3,680,465, 3,680,466 and 3,714,881 comprise a developer pack or container having a chamber for receiving developing fluid together with an exposed light sensitive film. A package in the form of an envelope containing a film-treating solution or fluid is disposed inside the chamber and has a pair of outwardly extending tabs secured to the container. A leading end of the fluid containing envelope projects through an outlet opening in the container while a trailing end of the envelope is provided with an aperture engagable with a tooth on the film. A user inserts a film wrap containing the film into an inlet opening of the container, whereupon the tooth on the film is hooked through the aperture on the envelope. The user then grips the leading end of the envelope and pulls the envelope together with the film through the container. The withdrawal of the envelope from the developing chamber of the container causes the envelope to rupture in the regions of the tabs, whereupon the film treating fluid flows from the envelope into the developing chamber of the container. The tooth on the film is released from the trailing end of the envelope upon the passage of the trailing end through the outlet opening of the container, whereby the film is positioned in the developing chamber. Subsequently, the user withdraws the film from the chamber by griping the tooth and pulling the film through the outlet opening of the container.
U.S. Pat. Nos. 3,646,872 and 3,646,873 are also directed to disposable film developers and film envelopes.
An object of the present invention is to provide an improved film developer of the above-described type.
A more specific object of the present invention is to provide such an improved film developer in which the transmission of light energy through the inlet opening and outlet opening of the container into the developing chamber is substantially eliminated.
Another more specific object of the present invention is to provide such an improved film developer in which the release of film treating fluid from the envelope into the developing chamber is controlled, preferably in both space and time.
Yet another object of the present invention is to provide such a film developer with improved means for rupturing the film containing envelope upon the withdrawal thereof from the developing chamber.